Background: Genomic instability, a hallmark of cancer, leads to copy number variations disrupting gene dosage balance and contributing to tumor progression. One of the most affected oncogenes is MYC, whose overexpression is tightly regulated to avoid cytotoxicity. In aneuploid cancer cells, gene dosage compensation mechanisms involving microRNAs (miRNAs) from the miR-17/92 cluster contribute in regulating MYC expression. Targeting this miRNA-mediated compensation system represents a promising therapeutic strategy leading to an uncontrolled and lethal MYC overexpression. Results: Synthetic miRNA sponges targeting miR-17, miR-19a, and miR-20a, key regulators of MYC dosage compensation, were designed and validated. Breast cancer cells (MCF7) with stable exogenous MYC overexpression were used to assess the impact of sponge constructs on MYC regulation. Quantitative RT-PCR revealed a significant reduction in miRNA expression and a corresponding increase in endogenous MYC levels upon sponge treatment. Functional assays in multiple colorectal cancer cell lines with varying MYC copy numbers demonstrated a time-dependent increase in cell death following sponge transfection. Cytotoxic effects increased with MYC copy number, confirming a correlation between gene dosage sensitivity and therapeutic response. Conclusions: Our findings demonstrate that miRNA sponges targeting the miR-17/92 cluster can effectively disrupt MYC dosage compensation, leading to selective cytotoxicity in MYC-amplified cancer cells.
The factors influencing the distribution and abundance of ectoparasites in vertebrates have been thoroughly examined in rodents, particularly concerning ticks and fleas. However, there is a paucity of knowledge regarding mites. The aim of this study was to determine if host or landscape traits are responsible for the abundance of dermanyssoid and trombiculoid mites. Rodent captures were carried out in the northwest region of Mexico between 2018 and 2022 in order to collect mites of the superfamilies Dermanyssoidea and Trombiculoidea. We generated generalized linear models to determine if rodent characteristics or the Index of Relative Anthropization (IRA) contribute to the relative abundance of Dermanyssoidea and Trombiculoidea. The best generalized linear model for Dermanyssoidea suggests that mite abundance is influenced by the IRA and the terrestrial rodent abundance. There is a relationship between the abundance of terrestrial rodents and dermanyssoid mites. Data show that as anthropization increases, Dermanyssoidea abundance decreases. The model shows rodent abundance, and the IRA are key factors in Trombiculoidea abundance. Our findings indicate that trombiculoid mites increase alongside rodents but decline as the IRA increases. This is the first study to use an index to investigate the impact of relative anthropization on Dermanyssoidea and Trombiculoidea in Mexico.
Rare actinomycetes are increasingly recognised as a valuable yet underexplored source of bioactive compounds with significant biomedical potential. While it is well established that bacteria have evolved adaptive mechanisms to withstand environmental stressors, such as variations in temperature, salinity or pH, our understanding of how these abiotic parameters influence bacterial metabolism remains limited. This has important implications not only for laboratory cultivation but also for predicting microbial behaviour in natural ecosystems. In this study, we investigated the effect of temperature on specialized metabolite production by the genus Rhodococcus. Seven strains isolated from marine sediments in three regions – Scotland, the sub-Arctic and Antarctica – were cultured at 20, 25 and 30 °C. Strain-specific growth curves were generated to normalize metabolite extraction at equivalent growth stages, resulting in a total of 54 Rhodococcus metabolite extracts. Liquid chromatography-high-resolution mass spectrometry analysis combined with molecular networking revealed that lower cultivation temperatures reduced bacterial biomass and delayed the onset of the stationary phase, and strain Rhodococcus KRD197 exhibited temperature shifts in metabolism that were associated with alterations in carbohydrate and fatty acid metabolism, potentially linked to osmotic regulation and cell membrane adaptation. These findings highlight the impact of temperature on Rhodococcus-specialized metabolism and support the potential of rare actinomycetes from extreme environments for expanding chemistry from these understudied genera.
Ambrosia beetles (Curculionidae: Scolytinae and Platypodinae) are wood-boring insects studied as examples of fungus-insect symbiosis and for their success as invasive species. While most research on their microbiota has focused on fungal associates, their bacterial communities remain largely understudied. In this review, we synthesize current knowledge on the bacterial microbiota of ambrosia beetles, identify critical gaps in the field, and provide recommendations for future research. To date, eight metabarcoding studies have explored bacterial communities in ambrosia beetles, analyzing a total of 13 species, mostly within the tribe Xyleborini (Scolytinae). These studies have examined the presence of bacteria in ambrosia beetle mycetangia, organs specialized for transporting fungal symbionts, as well as bacterial diversity in fungal gardens and whole beetles, across different life stages, and under varying environmental conditions. In general, bacterial communities appear to be highly specific to the beetle species, and differ between the beetles and their fungal gardens. Most studies employed 16S rRNA gene metabarcoding, and the optimal primer combination for characterizing bacterial communities in environmental samples is 515F/806RB (V4). Various methods for collecting beetles have been used, such as ethanol-baited traps, direct collection from galleries, logs kept in emergence cages, and rearing, but which of them to select when planning a study depends on the specific aim. A significant knowledge gap remains regarding the functional roles of dominant bacterial taxa, as metabarcoding studies often assume that these roles are similar to those played in other beetle species, such as bark beetles. More studies should be conducted to test hypotheses regarding the various factors influencing microbial composition and function, and advanced molecular techniques, including (meta-) genome and transcriptome sequencing, which have been employed in only a limited number of
Bartonella is a widely distributed Gram-negative bacterium that includes species that are capable of causing illness in humans. Rodents represent one of the main reservoirs of zoonotic pathogens, and monitoring their populations can provide valuable insights into human health. We conducted a surveillance study of rodents from two north-western states of Mexico (Baja California and Chihuahua) to investigate the prevalence and genetic diversity of Bartonella by polymerase chain reaction (PCR) amplification and sequencing of the citrate synthase (gltA) gene. A total of 586 rodents belonging to 28 species were captured, and 408 were tested for Bartonella spp. The overall Bartonella spp. prevalence was 39.71%. The prevalence found in Chihuahua was higher (42.80%) than in Baja California (32.52%), and rodents such as Neotoma albigula, Neotoma mexicana, Peromyscus boylii, and Chaetodipus baileyi had the highest prevalence. The gltA sequences revealed seven genetic variants, some of which were obtained from Peromyscus and Dipodomys rodents and were associated with Bartonella species of human health concern, such as B. grahamii and B. vinsonii subsp. arupensis. In addition, a sequence obtained from a Peromyscus maniculatus was clustered with Candidatus Bartonella rudakovii, a previously unreported association. This study provides valuable data and new insight into the Bartonella-hosts interactions in rodent species in north-western Mexico.
Sloths have the slowest digestion among mammals, requiring 5–20 times longer to digest food than other herbivores, which suggests differences in their gut microbiota, particularly in plant-fiber-degrading microorganisms. Bradypus variegatus has a lower metabolic rate and moves less than Choloepus hoffmanni. However, no comprehensive studies have compared the microbiota (e.g., fungi) of these species. We hypothesized that differences in digestion and metabolism between the two species would be reflected in their microbiota composition and functionality, which we characterized using metagenomics, metabarcoding, and cellulose degradation. Results revealed significant differences in microbiota composition and functionality. Both species are dominated by bacteria; fungi comprised only 0.06–0.5% of metagenomic reads. Neocallimastigomycota, an anaerobic fungus involved in fiber breakdown in other herbivores, was found in low abundance, especially in B. variegatus. Bacterial communities showed subtle differences: C. hoffmanni was dominated by Bacillota and Bacteroidota, while B. variegatus showed higher Actinomycetota. Expected herbivore bacterial taxa (e.g., Fibrobacter and Prevotella) were scarce. Functional analysis showed a low abundance of carbohydrate-active enzymes essential for polysaccharide breakdown. Cellulose degradation assays confirmed that sloths digest only ~ 3–30% of ingested plant material. This research sheds light on the potential multidirectional links between the gut microbiota, metabolism, and digestion.
Here, we report the draft genome sequences of four Bradyrhizobium spp. isolates obtained from root nodules of the native legumes Pentaclethra macroloba, Chamaecrista nictitans, Erythrina fusca and Zygia engelsingii in tropical forests of Costa Rica. Genomes ranged from 8.6 to 9.8 Mb with GC contents between 62.8% and 63.8%. Phylogenomic analysis, along with average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) comparisons, confirmed that these isolates represent potential new species. ANI values ranged from 88.3% to 90.3%, and dDDH values from 28.8% to 41.8%, compared with their closest Bradyrhizobium species. Functional annotation revealed some genes related to nitrogen fixation (nifA, nifB, nifH) and nodulation capacity (nodB, nodC, nodJ). These results provide insights into the diversity and symbiotic capabilities of Bradyrhizobium in tropical ecosystems.
Genome sequences of two Stenotrophomonas sp. strains are reported. Isolates were obtained from the venom of the tarantula Stichoplastoris elusinus (Araneae: Theraphosidae) and are closely related to the recently described Stenotrophomonas muris. The announcement highlights the presence of multiple antibiotic resistance genes and their relevance to veterinary and human health
More than half of the emerging or re-emerging pathogens that affect human health have their origin in wildlife. Among these rodents are key zoonotic hosts due to their unique characteristics of life history and species diversity. The latter, added to logistical complexities and financial constraints, represents a significant challenge for rodent-borne pathogens surveillance, particularly in regions such as Mexico and several countries in the Neotropics. This study examines host ecological traits associated with arenavirus and hepacivirus infections in American rodents and uses ecological trait-based models to identify potential hosts that have not yet been sampled. To achieve this, we compile data on positive rodent species for mammarenaviruses and hepaciviruses infections, along with records of rodent species that inhabit the American continent, ecological traits and phylogenetic information related to these species. Subsequently, boosted regression trees (BRT) were used to explore how well different ecological traits could forecast viral positivity in rodent hosts. The models exhibited high predictive accuracy, with AUC values ranging from 0.92 to 0.96 for hepacivirus and mammarenavirus. Viral positivity was associated with family affiliations such as Muridae and Cricetidae, and ecological traits such as body mass, litter size, and longevity. Ultimately, we identified 46 potential hosts that warrant further surveillance to detect these viral agents. The application of ecological trait-based models has the potential to optimize wildlife sampling and enhance the efficacy of monitoring initiatives, thereby facilitating the prediction and management of emerging infectious diseases.
Chagas disease, caused by Trypanosoma cruzi, remains a significant public health challenge, particularly in Latin America, where it is one of the most neglected diseases and is primarily transmitted by triatomine insects. The disease exhibits complexity due to its diverse transmission routes, including vectorial and non-vectorial mechanisms such as blood transfusions and congenital transmission. Effective monitoring and control strategies are critical to mitigating its impact. This review focuses on current monitoring and control efforts, emphasizing the importance of enhanced surveillance systems, improved risk assessments, and integrated vector control programs. Surveillance plays a pivotal role in early detection and timely intervention, particularly in endemic regions, while vector control remains central to reducing transmission. Moreover, the development of novel diagnostic tools, treatments, and vaccines is a crucial step in advancing control efforts. This review also highlights the involvement of local governments, international organizations, and civil society in executing these strategies, stressing the need for sustained political commitment to ensure the success of public health programs. By addressing key challenges in monitoring, control, and prevention, this review aims to provide insights and recommendations to further global efforts in reducing the burden of Chagas disease
Microbes are essential in every environment, with an important role in the fight against climate change. Promoting microbiology literacy, especially among children, is crucial. Our Ibero-American consortium uses gamification to make science and microbiology education engaging, tested through outreach campaigns in Costa Rica, and promoting future campaigns across Latin America.
Understanding the genetic diversity and connectivity of coral populations is necessary for their adequate management, especially considering global climate change. This study reports the genetic diversity and structure of the most common coral genus in the Eastern Tropical Pacific, Pocillopora. A total of 12 microsatellite loci were tested to estimate genetic diversity metrics for three populations in the Gulf of Papagayo, of which 11 amplified successfully. High level of clonality was found in one of the populations (Jícaro; clonal richness, R = 0.069), where only three multilocus genotypes (MLGs) were found. This population also exhibited the lowest heterozygosity (He = 0.364) compared to Matapalo (He = 0.624) and Zapotillal (He = 0.598). Genetic structure was assessed using Nei’s pairwise FST and complemented with assignment tests. The analyses found Jícaro to be differentiated from both Matapalo and Zapotillal; whereas the last two populations show reduced divergence between them. These results indicate predominant asexual reproduction in Jícaro. Coupled with genetic isolation with the other sites suggest the occurrence of different Pocillopora species. Anyhow, they highlight a reduced genetic diversity, and thus a high vulnerability, in Jícaro.
Endohyphal microbial communities, composed of bacteria and viruses residing within fungal hyphae, play important roles in shaping fungal phenotypes, host interactions, and ecological functions. While endohyphal bacteria have been shown to influence fungal pathogenicity, secondary metabolism, and adaptability, much remains unknown about their diversity and host specificity. Even less is known about endohyphal viruses, whose ecological roles and evolutionary dynamics are poorly understood. This study integrates genomic and transcriptomic approaches to (1) characterize the diversity of endohyphal bacterial and viral communities in fungal endophytes isolated from Fagus grandifolia leaves, and (2) assess potential host specialization through phylogenetic signal analyses.
Brazil harbors the greatest diversity of primates, and among them, the genus Callithrix is notable for its adaptation to urban environments. Despite being endemic to southern Bahia and northeastern Minas Gerais, the Wied's marmoset (Callithrix kuhlii) remains understudied, highlighting the need for baseline health data. This study aimed to characterize the hematological and biochemical profiles of C. kuhlii in urban and peri-urban areas within its distribution range. A total of 106 wild marmosets were captured, and blood samples were collected from the femoral plexus of the individuals. Hematological parameters showed no significant differences between sexes. However, sex-based variations were observed in serum biochemistry, with males showing higher triglycerides and urea levels, possibly influenced by dietary factors and testosterone. This pioneering study establishes essential baseline data on the hematology and biochemistry parameters of C. kuhlii in the wild, supporting future research on its ecology and conservation within the Atlantic Forest.
Count models are used when the response variable represents the number of specific successes. Depending on the application area, this count may have an excess of zeros, which requires a model that addresses this detail. Zero-inflated models are ideal for such situations. This study analyzes data related to Chagas disease to address both statistical and biological questions. To achieve this, a simulation study is conducted to determine whether variations in sample size affect estimates and if the chosen sampling method influences the performance of metrics used to calculate the probability of cell infection. It is found that balancing the sample size across concentrations using stratified sampling yields the best metric performance values. Additionally, it is concluded that increasing the concentration dose helps to reduce the number of parasites in the cells.
Fruits of Costa Rican guava (Psidium friedrichsthalianum (O. Berg) Nied) contain phenolic compounds and offer the possibility of creating novel functional foods with benefits for human health. In vitro culture, a propagation technique currently scarce for this species, can be developed for the propagation of genotypes with desirable fruit and agronomic traits. Woody Plant Medium supplemented with the growth regulators 6-benzylaminopurine, kinetin and gibberellic acid at concentrations of 0.5, 1.0 and 1.5 mg/L was used. Microcutting resulted in a more favorable response to BAP for variables such as the number of shoots (NS), number of nodes (NN) and number of leaves (NL). The mean NS was 4.80 when 1.5 mg/L BAP was used, whereas the optimal response for NN (14.73), NL (30.73), and shoot length (SL) (2.2 cm) was 0.5 mg/L BAP. WPM was subsequently supplemented with 0.5 mg/L BAP for multiplication in RITA®. The number of shoots (6.33 ± 2.31) and multiplication coefficient (5.33 ± 2.31) were greater than those of the semisolid media, with values of 4.30 ± 1.32 and 3.30 ± 1.32, respectively. For the rooting phase, the greatest response to the number of roots (3.75 ± 2.79), root length (2.46 ± 1.61 cm) and plant height (7.00 ± 0.63 cm) was associated with 0.3 mg/L indol-3-butyric acid. The survival rate of the rooted plantlets in the greenhouse was greater than 90% when the plants were exposed to IBA. This work provides new knowledge to the scarce literature on in vitro culture of P. friedrichsthalianum, particularly on the use of RITA®, which is described for the first time. New contributions to rooting and acclimatization for this species are comprehensively detailed.
The extensive use of pharmaceuticals has led to their occurrence in surface waters due to insufficient treatment processes for their removal. Their environmental impact remains largely unexplored for certain trophic levels, particularly plants and algae. Pharmaceuticals often occur in mixtures with other pollutants, highlighting the need for comprehensive toxicological assessments that evaluate their combined interactions. This study evaluated the acute toxicity of four high-hazard pharmaceuticals —diphenhydramine, fluoxetine, ketoprofen, and trimethoprim— and their binary mixtures, on the green microalgae Raphidocelis subcapitata and the aquatic macrophyte Lemna gibba. For individual compounds, R. subcapitata growth rate was inhibited in all cases, with fluoxetine, ketoprofen and diphenhydramine exhibiting moderate toxicity (EC50 = 0.34, 0.14, and 4.88 mg/L, respectively), while trimethoprim showed low toxicity (EC50 = 332.35 mg/L). Similar trends were observed in L. gibba, except for diphenhydramine, which also showed low toxicity (EC50 = 26.57 mg/L). Binary mixtures demonstrated a synergistic interaction towards the microalgae in the presence of ketoprofen, except ketoprofen-trimethoprim combination (antagonism, p < 0.0001). In contrast, most interactions in L. gibba exhibited antagonism, except ketoprofen-fluoxetine (synergism, p = 0.0042). Differences were observed between the two model organisms for individual compounds and mixtures. No correlation was found between L. gibba experimental data and QSAR predictions derived from R. subcapitata. Our results highlight the need for: i. further studies including mixtures of relevant pharmaceuticals; ii. caution in the use of predictive models or extrapolation between taxa; and iii. the inclusion of fluoxetine and ketoprofen as priority compounds in future risk assessments.
Scientific research seeks to extend knowledge and understanding, an activity that perhaps more than any other advances society and humanity. In essence, it is the search for truth. But, because it seeks new knowledge, there is little or no benchmark for appraisal of the plausibility or validity of the immediate conclusions drawn from new information gained, no instant confirmation. For this and other reasons, the science ethos requires the highest level of rigour to ensure the highest level of probability that new findings are true, or at least the most plausible under the prevailing circumstances and state of knowledge. Research is only as good as its degree of rigour. Rigour comes through intensive and comprehensive scientific training and mentoring that teaches critical and agnostic evaluation of new results, self-scrutiny and self-criticism. Additional rigour comes via independent scrutiny and validation: peer review of results and interpretations submitted as publications, and peer repetition of key experiments. However, the current proliferation of publication vehicles whose business model is based on maximisation of papers published, and the revenue stream of article processing charges (APCs) they generate, is promoting an insidious degradation of rigour and quality standards of reviewing–editing practices. Such predatory practices result in the systematic degradation of research quality and its “truthfulness”. Moreover, they undermine the science ethos and threaten to create a new generation of scientists that lack this ethos. These trends will inevitably progressively erode public trust in scientists and the research ecosystem. This Editorial is a call for action to all actors, in particular leaders, in scientific research to oppose predatory practices in science dissemination—to restrict the operational space of those responsible for such practices—in order to restore and maintain research rigour and the science ethos and to prevent a downward spiral of re
In today’s landscape of zoonotic pathogen outbreaks, the dilution effect theory, i.e., the theory that greater biodiversity can help curb pathogen transmission among wildlife, has gained significant attention. However, the positive link between animal diversity and pathogen richness urges us to apply this concept with caution. It is crucial to explore how conservation biology can safeguard human health by preventing the emergence of zoonotic diseases. By investigating the implications of conservation strategies on animal communities and pathogen transmission as well as the adaptive capabilities of pathogens, we propose that biodiversity conservation based on small reserves can effectively reduce pathogen spread in wildlife, provided certain measurable conditions are met. Given the urgent need to tackle both zoonoses disease emergence and biodiversity loss, these interventions should be prioritized and implemented without delay.
Liquid organic fertilizers (LOF) or bioles are liquid bioinput products derived from the fermentation of vegetable and fruit wastes, manure, waste from the dairy industry, and others; their metabolic and microbiological composition varies according to the source of its raw material. Its biostimulant effect has been demonstrated on various crops of agronomic interest in some Latin American countries, such as Costa Rica, where it is produced in an artisanal way. To our knowledge, this is the first literature review of LOF from a technical perspective, showing the stages of their fermentation process, as well as factors that may affect it, and technological tools that will allow us to monitor their quality and safe application in crops. We found that the application of this traditional and local practice has great potential to be projected worldwide; however, more research is needed to standardize its composition and effects according to the type of crop. The use of biotechnological tools for making LOF would allow the determination of their metabolic and microbiological composition and, at the same time, the monitoring of the quality of the product, allowing its safe use in agriculture. Finally, the production and application of LOF within a sustainable agricultural model would favor a circular economy by using organic waste as a raw material, thereby reducing the cost of chemical product consumption.
Dutch elm disease (DED) has caused devastating pandemics in natural elm populations across Europe, North America, and Asia. The primary vectors of DED are native elm-associated bark beetles of the genus Scolytus. However, there is evidence suggesting that ambrosia beetles may also carry Ophiostoma novo-ulmi and potentially transmit it to elm trees. In this study, we explored microbial interactions and host selection mechanisms that could support the role of ambrosia beetles as vectors of O. novo-ulmi. Our study showed that females of Anisandrus dispar, Xyleborinus saxesenii, Xylosandrus crassiusculus, and Xylosandrus germanus emerging from both DED-infected and healthy elm logs carried O. novo-ulmi DNA. Furthermore, we showed that none of the tested ambrosia beetle fungal symbionts was adversely affected by O. novo-ulmi, while Dryadomyces spp. and the bacterial symbiont Erwinia sp. 1C4 partially restricted or inhibited O. novo-ulmi growth without fully suppressing it. Overall, these findings provide additional evidence supporting the potential role of ambrosia beetles as vectors of DED and emphasize the need for further research on this understudied insect-pathogen relationship.
In Brazil, Plasmodium infections in non-human primates (NHPs) have been associated with P. simium and P. brasilianum, which are morphologically and genetically similar to the human-infecting species P. vivax and P. malariae, respectively. Surveillance and monitoring of wild NHPs are crucial for understanding the distribution of these parasites and assessing the risk of zoonotic transmission. This study aimed to detect the presence of Plasmodium spp. genetic material in Platyrrhini primates from 47 municipalities in the states of Bahia and Minas Gerais. The animals were captured using Tomahawk-type live traps baited with fruit or immobilized with tranquilizer darts. Free-ranging individuals were chemically restrained via inhalation anesthesia using VetBag® or intramuscular anesthesia injection. Blood samples were collected from the femoral vein. A total of 298 blood and tissue samples were collected from 10 primate species across five genera: Alouatta caraya (25), Alouatta guariba clamitans (1), Callicebus melanochir (1), Callithrix geoffroyi (28), Callithrix jacchus (4), Callithrix kuhlii (31), Callithrix penicillata (175), Callithrix spp. hybrids (15), Leontopithecus chrysomelas (16), Sapajus robustus (1), and Sapajus xanthosthernos (1). Molecular diagnosis was performed using a nested PCR targeting the 18S small subunit ribosomal RNA (18S SSU rRNA) gene, followed by sequencing. Of the 298 samples analyzed, only one (0.3%) from Bahia tested positive for Plasmodium brasilianum/P. malariae. This represents the first detection of this parasite in a free-living C. geoffroyi in Brazil. These findings highlight the importance of continued surveillance of Plasmodium infections in NHPs to identify regions at risk for zoonotic transmission.
Chikungunya virus (CHIKV) is primarily associated with non-human-primates (NHPs) in Africa, which also infect humans. Since its introduction to Brazil in 2014, CHIKV has predominantly thrived in urban cycles, involving Aedes aegypti mosquitoes. Limited knowledge exists regarding CHIKV occurrence and implications in rural and sylvatic cycles where neotropical NHPs are potential hosts, from which we highlight Leontopithecus chrysomelas (Kuhl, 1820), the golden-headed lion tamarin (GHLT), an endangered species endemic to the Atlantic Forest (AF) in Southern Bahia State, Brazil. The present study investigated wild GHLT groups across two municipalities, Ilhéus and Una, Bahia. Surveys were conducted in three groups within cocoa agroforests (cabrucas) in Ilhéus, and four groups in anthropized forest and agroforestry fragments in Una, between 2021 and 2022. Thirty-two GHLT specimens were captured and chemically immobilized, examined and submitted to blood sample collection; nine specimens were later recaptured in 2022, totaling 41 samples. CHIKV viremia was not detected in any specimens (as assayed by RT-qPCR). Plaque reduction neutralization test (PRNT90) detected CHIKV antibodies in two (6.3%) GHLTs, with 10–20 antibody titers. Seroprevalence in 2021 was 5.6% and in 2022 was 8.7% with an incidence of 4.5%, whereas, a male adult tested seropositive in both years, suggesting either natural re-exposure and antibody maintenance over time. All samples tested seronegative for Mayaro Virus. Eight mosquito species from the Culicidae family were collected, identified and assayed for CHIKV genomes, showing negative results. This study provides the first evidence of natural CHIKV exposure among free-living GHLTs in Brazil, emphasizing their susceptibility and potential role as reservoirs. These findings underscore the possible consequences of anthropic disturbances in the Brazilian AF, without a seroprevalence difference between non-protected forest formations, agroforest fragments
Los propóleos son subproductos apícolas elaborados por abejas del género Apis mellifera y de otras especies, que presentan muchos tipos de bioactividad. Su origen y composición puede relacionarse con el entorno botánico del sitio de anidación de las abejas, tal es el caso de la planta Clusia valerioi (Standl.), especie endémica de Costa Rica, cuya flor produce una resina utilizada por las abejas que la visitan para la producción de propóleo. Lo anterior implica la posibilidad de establecer una trazabilidad de la composición química de la resina de la flor de C. valerioi y de los propóleos recolectados de apiarios ubicados en la Zona Sur de Costa Rica, en términos de relacionar la presencia de compuestos tipo flavonoides, ácidos fenólicos y del tipo benzofenonas policíclicas polipreniladas (nemorosoma) en ambos tipos de matrices, para la identificación de posibles biomarcadores activos para futuros estudios. Extractos etanólicos de muestras de propóleo de ocho apiarios visitados y extractos etanólicos de resina floral de C. valerioi de cuatro sitios cercanos a dos de estos apiarios, muestreados en la zona de Coto Brus (Costa Rica), fueron analizados y derivatizados con técnicas de HPTLC. Se estableció la presencia de 3 marcadores químicos importantes en el análisis (denominados como compuestos A, B y C), a partir de espectros de resonancia magnética nuclear de protones (1H-NMR) y carbono-13 (13C-RMN), espectros de absorción y cromatografías para 16 extractos de propóleos, resinas y flores C. valerioi. Se identificó el compuesto A como un compuesto derivado de los terpenos, el compuesto B como nemorosona y el compuesto C como un derivado de los flavonoides del tipo flavonol o flavonona.
Rice is a vital crop that feeds about two-thirds of the global population and plays a critical role in food security in countries such as Costa Rica. Salinity stress, however, severely limits rice productivity. Mutation breeding, particularly through gamma radiation, is effective for developing salt-tolerant varieties. In this study, embryogenic calli of Oryza sativa L. var. indica (CR-5272) were irradiated with 40 Gy of gamma rays and regenerated into M3 mutant lines. These were screened for salt tolerance under 150 mM NaCl using both in vitro and hydroponic systems. Morphological differences, especially in root development, differentiated tolerant and sensitive mutant lines. To assess molecular responses, we analyzed the expression of four salt stress-associated genes—CYSB, SAMDC, SAMS, and HKT2—previously reported as markers of salinity tolerance. Gene expression analysis via qRT-PCR revealed contrasting expression profiles of the selected salt-responsive genes in foliar and root tissues, distinguishing tolerant mutants from control plants. This study demonstrates the utility of combining gamma irradiation with molecular screening to identify promising salt-tolerant rice lines. Our findings contribute to the development of improved cultivars and support the use of known genetic markers to monitor stress responses in mutant populations.
We live in a time of global crises: a deteriorating environment that is struggling to provide all the resources and services we demand of it, changing climate and its consequences for the biosphere, its habitats, inhabitants and biodiversity, conflicts-divisive ideologies-competition for resources, increasing societal inequalities and human deprivations, and a youth mental health pandemic, to name but just a few. Most of these crises are self-made, the result of human decisions, and their acceptance/toleration by society. Policies and practices at all levels of society that created, exacerbate and launch new crises are, at worst, self-serving and, at best, faulted through a lack of understanding. In democracies, citizens can hold decision-makers to account but, to do this, they must understand the issues and be able to imagine better policies. We also live in a digital world in which a flood of mostly inconsequential information and misinformation pollutes our brains, enhancing pre-existing biases and creating new ones, and numbing our mental ability to think clearly and reach sensible decisions. But sensible decisions are urgently needed at all levels to fix problems and reduce future self-harm. Sensible decisions require sourcing the best available relevant information, and a process to convert information into understanding, understanding into clear decision options, and the choice of a decision option that leads to an action that represents best practice. Critical thinking is the enabling cognitive process of this decision pathway, because it selects the best available information through demanding evidence-basing, seeks critical discourse between experts and stakeholders that agnostically explores solution space to find plausible options, and whittles down options inter alia through plausibility, due diligence, bottleneck analysis, cost-benefit analysis, and benchmarking filtering. Crucially, it rejects biases, influencing factors, and other constraints on opti
Microbes govern our planet! The International Microbial Literacy Initiative (IMiLI) promotes global microbial literacy with free, open-access resources in multiple languages. Understanding microbes is key to sustainability and informed decision-making.
Teak (Tectona grandis L.f), a valuable hardwood species, is widely cultivated for its superior wood properties. Effective breeding and clonal propagation programs require robust genetic verification methods such as clonal fidelity and parentage verification when these programs include controlled cross-pollination and propagation of elite clones. This study validates the use of ten optimized microsatellite markers in a multiplex PCR system for clonal identification and parentage testing. The system showed high discrimination power, with probabilities of identity (PI) and exclusion (PE), confirming its efficacy. The ten markers accurately identified clonal fidelity and ensured genetic fidelity of progenies. Overall, the study confirms effectiveness of microsatellites for genetic analysis and highlights a cost effective and precise approach for breeding and clonal propagation of teak.
As scientists, change is the only constant in our journey. We often find ourselves in transition from one laboratory to another, and during our training we are fortunate to experience the excitement of pursuing postgraduate studies abroad in well-funded, high-level research centers. However, after completing doctoral or postdoctoral training, we are frequently drawn to return to our home countries, where funding and support for science are significantly more limited. In this brief commentary, first, I would like to highlight the challenges faced by scientists from developing countries who have had the opportunity to train internationally and then choose to return home, driven both by personal motivations (e.g., family) and by the desire to contribute to the scientific advancement of their regions. Second, I would like to share some advice that has been especially useful to me in establishing my laboratory, defining research topics, and maintaining academic productivity. I hope these insights can be useful to colleagues in similar situations across different regions. Although starting a research group in regions with less investment in Research and Development is challenging, it is achievable with perseverance and the implementation of concrete actions.